- instant (n.)
- late 14c., "infinitely short space of time," from O.Fr. instant (adj.) "assiduous, at hand," from M.L. instantem (nom. instans), from L. instantem "present, pressing, urgent," prp. of instare "to urge, to stand near, be present (to urge one's case)," from in- "in" + stare "to stand," from PIE base *sta- "to stand" (see stet). Elliptical use of the O.Fr. adj. as a noun. New Latinate adj. form instantaneous is attested from 1650s.